Still puzzled about it.
Is the aerodynamic moment a "theoretical" thing?
¿Can we use any point of reference we want?
Let's assume an airplane with the CG exactly in the CP, in trim, steady level flight. How much tail lift does it have? How much is the ANU moment it has to balance? Does it depend on what point we choose for the moments? That would make no sense...
When I think of a moment, I think of a force and an arm. Moments will vary depending on the point selected, of course. When talking about the aerodynamic center, Where is the force?